1. Technical Field
The present technology relates to a pneumatic tire for mounting on a vehicle.
2. Related Art
Pneumatic tires for mounting on vehicles such as automobiles and the like are known that have a portion (serration) in a side wall portion of the tire where multiple ridges are formed at a short pitch, the ridges being constituted by small, linear protrusions or recesses. For example, in Japanese Patent No. 3645358, a pneumatic tire in which a circular decorative body is provided on a surface of a side wall is described, the circular decorative body being formed from multiple small ridges having a height of not more than about 2 mm, disposed at a small pitch of not more than about 5 mm in a circumferential direction. Additionally, with the pneumatic tire described in Japanese Patent No. 3645358, the circular decorative body is divided into a plurality of crescentic decorative bodies on the periphery by a narrow band-like dividing band that extends in a direction inclined at a large angle, with respect to a radial direction, of not less than 70° and less than 90°. The ridges extend substantially parallel to each other within the same crescentic decorative body, and extend in a different direction in a contiguous crescentic decorative body.
Additionally, in Japanese Unexamined Patent Application Publication No. H06-106921A, a pneumatic tire is described in which a side wall portion is divided into a plurality of fan-shaped regions in a tire circumferential direction, wherein a difference between surface roughness of contiguous fan-shaped regions is not less than 50 μm.
As with the pneumatic tire described in Japanese Patent No. 3645358, appearance flaws of a tire can be improved by forming a serration in the side wall of the tire, the serration being constituted by multiple ridges. However, with the pneumatic tire described in Japanese Patent No. 3645358, unevennesses in the side wall portion of the tire, specifically at carcass splice portions and portions where the carcass is folded up, may not be sufficiently camouflaged. Thus, there are cases where improvement of the quality of the appearance of the tire is insufficient. Additionally, in some cases, camouflaging properties are insufficient even when the surface roughness for each region divided into a plurality of sections in the circumferential direction is varied, as described in Japanese Unexamined Patent Application Publication No. H06-106921A and, thus, improvement of the quality of the appearance of the tire may be insufficient.